According to <a href="">NASA scientists</a>, the Voyager 1 spacecraft entered interstellar space in August 2012, becoming the first spacecraft to leave the <a href="/our_solar_system/solar_system.html&dev=1">solar system</a>. The space probe is about 19 billion km from the <a href="/sun/sun.html&dev=1">Sun</a>.  <a href="/space_missions/voyager.html&dev=1">Voyager 1 and 2</a> were launched in 1977 on a <a href="/space_missions/voyager.html&dev=1">mission</a> that flew them both by <a href="/jupiter/jupiter.html&dev=1">Jupiter</a> and <a href="/saturn/saturn.html&dev=1">Saturn</a>, with Voyager 2 continuing to <a href="/uranus/uranus.html&dev=1">Uranus</a> and <a href="/neptune/neptune.html&dev=1">Neptune</a>. Voyager 2 is the longest continuously operated spacecraft. It is about 15 billion km away from the <a href="/sun/sun.html&dev=1">Sun</a>.<p><small><em>Image courtesy of NASA</em></small></p>An <a href="">8.6 magnitude earthquake</a> struck on 11 April 2012 off of Banda Aceh, Sumatra, Indonesia, followed by a strong aftershock.  Earthquake motion was primarily horizontal.  A tsunami warning was issued for the Indian Ocean, but was cancelled at 12:36 UTC.  A tsunami was observed at 1 meter or less. Find out more about <a href="/earth/geology/quake_1.html&dev=1">earthquake</a> and <a href="/earth/tsunami1.html&dev=1">tsunami</a> processes. Check out the resources <a href="/teacher_resources/2011_AGU-NESTA_GIFT_Workshop.html&dev=1">here</a>.<p><small><em>NOAA</em></small></p>This historic image is the first ever taken from a spacecraft in orbit about <a href="/mercury/mercury.html&dev=1">Mercury</a>, the innermost planet of the solar system.  Taken on 3/29/2011 by <a href="/space_missions/robotic/messenger/messenger.html&dev=1">MESSENGER</a>, it shows numerous craters across the <a href="/mercury/Interior_Surface/Surface/surface_overview.html&dev=1">surface</a> of the planet.  Temperatures there can reach over 800F because Mercury is so close to the Sun and rotates so slowly.  MESSENGER entered orbit around Mercury earlier in March 2011.<p><small><em>NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington</em></small></p><p>The United Nations <a href="" target="_blank">estimated</a> that between 1994-2015, there were 6,873 natural disasters worldwide, which affected 218 million people and claimed 1.35 million lives. </p>
<p>Check out the materials about natural disasters in <a href="/earth/natural_hazards/when_nature_strikes.html&dev=1">NBC Learn Videos</a>, and their earth system science connections built up by the related secondary classroom activities.</p><p><small><em>NBC Learn</em></small></p>Scientists at the University of Michigan have found that <a href="/earth/polar/cryosphere_permafrost1.html&dev=1">permafrost</a> in the <a href="/earth/polar/polar_north.html&dev=1">Arctic</a> is extremely sensitive to sunlight.  Exposure to sunlight releases carbon gases trapped in the permafrost, including <a href="/earth/climate/earth_greenhouse.html&dev=1">climate-warming</a> <a href="/physical_science/chemistry/carbon_dioxide.html&dev=1">carbon dioxide</a>, to the <a href="/earth/Atmosphere/overview.html&dev=1">atmosphere</a> much faster than previously thought.<p><small><em>George Kling, The University of Michigan</em></small></p>A <a href="">study</a> of over 40,000 written entries in Irish Annals and ice core measurements shows a strong correlation between <a href="">volcanic eruptions</a> and extreme cold weather in Ireland over a 1200 year period, from 431 to 1649.  During this time up to 48 volcanic eruptions were identified in Greenland ice core records through deposition of volcanic sulfate in annual layers of ice. Find out more about <a href="">volcanoes and climate</a>.<p><small><em>Image Courtesy of Marco Fulle</em></small></p>

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